Bruxism is a term that refers to excessive grinding and clenching of the teeth. Those with bruxism are often unaware that they have developed this habit, and often do not know that treatment is available until damage to the mouth and teeth has been done. Each individual may experience different symptoms which may include: abraded teeth, facial pain, oversensitive teeth, tense facial and jaw muscles, headaches, dislocation of the jaw, damage to the tooth enamel, exposing the inside of the tooth (dentin), a popping or clicking in the temporomandibular joint (TMJ), tongue indentations, and/or damage to the inside of the cheek.
While the causes of bruxism are sometimes not known or not recognized, oral health specialists often point to excessive stress and certain personality types as being associated with bruxism. Bruxism often affects persons with nervous tension such as anger, pain, or frustration, and/or persons with aggressive, hurried, or overly competitive tendencies.
Bruxism may be diagnosed during dental examinations, and may, for example, be indicated by the upper surfaces of the teeth appearing flat. If symptoms are present, the condition is usually observed for changes over the next several visits before a treatment program is established.
Specific treatment for bruxism may be determined by a dentist or physician based on one or more factors, such as the person's age, overall health, medical history, severity of symptoms, patient or doctor preference, and tolerance for specific medications, procedures, or therapies.
In many cases, bruxism can be successfully treated by:
a. Behavior modification achieved through instruction from an expert regarding helping the patient learn to rest his/her tongue, teeth, and lips properly, and/or how to rest his/her tongue upward while keeping the teeth apart and lips closed to relieve discomfort on the jaw.b. A specially-fitted plastic mouth appliance may be worn at night to absorb the force of biting. This appliance may help to prevent future damage to the teeth and aid in changing the patient's behavior.c. Biofeedback which involves an electronic instrument that measures the amount of muscle activity of the mouth and jaw—indicating to the patient when too much muscle activity is taking place so that the behavior can be changed. This is especially helpful for daytime bruxers.
Bruxism patients may present with a variety of symptoms, including anxiety, stress, tension, depression, earache, eating disorders, insomnia, headache and/or jaw pain. Eventually, bruxing shortens and blunts the teeth being ground, and may lead to myofacial muscle pain, temporomandibular joint dysfunction and headaches. In severe, chronic cases, it can lead to arthritis of the temporomandibular joints. The jaw clenching that often accompanies bruxism can be an unconscious neuromuscular daytime activity, which should be treated as well, usually through physical therapy, such as recognition and stress response reduction.
Prior art bruxism management techniques include minimizing the abrasion of tooth surfaces by the wearing of an acrylic dental guard or splint, designed in the shape of an individual's upper or lower teeth from a bite mold. Mouth guards are obtained through visits to a dentist for measuring, fitting, and ongoing supervision. These devices use one or more of four approaches: constraint of dental movement such that serious damage to the temperomandibular joints is prevented, stabilization of occlusion by minimizing the gradual changes to the positions of the teeth that typically occur with bruxism, prevention of tooth damage, and the enabling of a bruxism practitioner to judge in broad terms the extent and patterns of bruxism, for example, through examination of physical indentations on the surface of a worn dental guard. Dental guards typically worn over an extended period during many night's sleep, may be seen in U.S. Pat. Nos. 4,976,618, 5,873,365, and 6,152,138. Another type of device sometimes given to a bruxer is a repositioning splint which may look similar to a traditional night guard, but is designed to change the occlusion or “bite” of the patient.
Bruxism is associated with a person's mandible which is connected to the cranium by the temporomandibular joints located immediately in front of the ears. Rotation of the mandible about these joints is accomplished by the masticatory muscles, each of which extends from an opposite side of the mandible to a connecting point on the cranial bones. The masticatory muscles have an at rest position between their extended and contracted states. Under normal physiological conditions involving the outgrowth of a full complement of teeth, the mandibular portion of each temporomandibular joint will rest lightly in the cranial portion of the joint, and the muscles will be relaxed or at rest.
Masticatory muscle related strain and/or pain can arise due to differences in occlusal pressures along the upper and lower dental arches. Temporomandibular joint dysfunction syndrome relates to occlusion-muscle incompatibility. Masticatory muscle accommodation is a key factor in the etiology of this syndrome. Psychological tension and stress can lead to temporomandibular joint dysfunction or bruxism in otherwise stable mouths with normal occlusion.
The most frequent jaw movement involves elevation of the mandible from its rest position into centric occlusion. Simple elevation of the mandible is normally powered almost entirely by the elevator muscles, other muscles providing only a minor bracing action. The bilateral temporals, masseters and medial pterygoids provide an excess supply of elevator motor units. Since these motor units alternate in function, with fatigued units relaxing to rest while others take their place, mandible elevation can be continued over long periods of time without over fatiguing these muscles.
Occlusion-muscle dysfunction alters this condition drastically because accommodation has a highly selective effect on the masticatory muscles, increasing their activity disproportionately in certain areas of the bilateral complex. In the presence of occlusion muscle disharmony, a traumatic closure into centric occlusion requires that the mandible be adjusted every time it is elevated into occlusion. If, for example, the required adjustment is horizontal, the muscle areas capable of producing such horizontal movements must be called into activity with the same frequency as are the elevator muscle areas. Unfortunately, there are far fewer of these horizontal-adjustor motor units than elevator motor units.
Ultimately, the functional capacity of these comparatively few horizontal motor units is exceeded, which triggers an exhaustion-in coordination-spasm sequence and development of the temporomandibular joint syndrome symptoms. The resulting tenderness and spasms are found most frequently in the lateral pterygoid muscles which function as anterior adjustors of mandibular placement.
In psychological stress related syndromes, the muscles become fatigued as a result of nocturnal clenching or grinding of the teeth. These nocturnal activities give rise to the same symptoms as malocclusion-based temporomandibular joint dysfunction.
The sequence of muscle dysfunction can spread beyond the masticatory muscles, producing a constellation of primary symptoms of the temporomandibular joint pain-dysfunction syndrome. These symptoms include pain and/or tenderness in the temporomandibular joint area or masticatory muscles; “clicking” in the temporomandibular joint; limitation of jaw opening; restriction of jaw movement; and secondary symptoms which are medical in nature, being transmitted to other, more distant areas of the head and neck. These secondary symptoms probably include some of the most widespread and problematic conditions medicine has to deal with, namely, headache (including “tension” headaches), atypical facial neuralgias, tinnitus and neck and ear pain, among others. Also, certain neuromuscular disorders of the face, head and neck, shoulders, back, arms and hands can occur. These secondary symptoms are functional disturbances which exhibit no organic changes in the affected tissues, making diagnosis difficult. They are often ill-defined and difficult for the patient to describe.
These symptoms are usually diagnosed as purely medical in nature because they occur at some distance from the teeth. Their masticatory muscle origin, unfortunately, is not readily apparent. The usual result is that treatment is mistakenly directed to the secondary symptom's locale rather than to the underlying malocclusion. Such malocclusions are common but difficult to detect. Intercuspation of the teeth appears normal, while the underlying faulty (accommodation-necessitating) craniomandibular relationship is hidden by the automatic compensatory action of the muscles. The secondary symptoms resulting from temporomandibular joint dysfunction thus are usually treated palliatively instead of having their basic cause eliminated. For malocclusion-based muscle dysfunction, definitive therapy is essentially an orthopedic procedure and requires correction of the faulty cranio-mandibular relationship by a dentist. For psychological stress-related dysfunctions, treatment may be addressed in other ways.
Some notable prior art methods of treating temporomandibular joint dysfunction and bruxism include clinical monitoring devices to measure the amount of pressure being asserted, splints to be worn during sleep to prevent the wearing of teeth, and behavior modification devices, which provide an electrical shock to the jaw muscles to interrupt nocturnal bruxing episodes without waking the patient.